A product development project is a temporary endeavor undertaken to develop a new product or service. An enterprise may use a product development pipeline to organize and optimize the allocation of resources for a stream of product development projects. Such resources may include time, money, people, materials, energy, space, equipment, communication, quality assurance, and risk tolerance. A product development pipeline consists of a chain of processes and resources arranged so that the output of each element of the chain flows into the input of the next element in the product development pipeline.